Soil Classification Civil Engineering and Architecture

1. Soil Classification Civil Engineering and Architecture Unit 4 – Site Planning

3. In this lesson: • Discuss the types of materials generally labeled as soil • Describe the characteristics of soil components

4. What is Soil? Gravel Clay Silt Sand

5. Testing the Soil Bearing Capacity Settling Characteristics Drainage

6. Site Planning Function of Structure Site Profile (Contour Map) Geological Information Soils Sample Data

7. Soil Samples • Samples Represent the Site • Taken about 1’-2’ below surface • Boring samples are taken at various locations and depths below the surface (subsurface) for deep foundations.

8. Unified Soil Classification System • Coarse-Grained Soils Fine Grained Soils Highly Organic Soils Professional Development Lesson ID Code: 8006

9. Unified Soil Classification System

10. Gravels range from 3” down to the size of peas. Silt and clay can pass through the #200 sieve. Sieve Sizes

11. Grain Size Click here to open the Grain Size Chart.

12. Gravel Identification

13. Sand Identification

14. Graded Soil • Well-Graded Soils-have a good representation of all particle sizes from the largest to smallest • Poorly-Graded Soils-two types • Uniformly-has soil particles nearly the same size. • Gap-Graded-contains both large and small particles but the graduation continuity is broken by the absence of some particle sizes.

15. Clean vs. Dirty Graded Soil • Clean: contains little or no fines (<5%) • Dirty: contains an appreciable amount of fines ( >12%)

16. Clay or Silt? • Dry Strength – crushing characteristics • Dilatancy – reaction to shaking • Toughness – consistency near plastic limit

17. Grain Shape

18. Soil Color • * Can vary with moisture content • * May indicate the presence of certain chemical or impurities • * Dark brown /black may indicate organic material. • * Gray, olive green indicate inorganic soils. • * Gray-blue or gray-yellow indicates poor drainage. • * Red or yellow may indicate iron oxides. • * White to pink may indicate considerable silica, calcium carbonate, or aluminum compounds.

19. Plasticity Atterberg Limits: Plastic Limit-lowest moisture content at which soils can be rolled into 1/8” diameter thread without breaking. Liquid Limit- minimum moisture content at which soil will flow when a small shear or cutting force is applied.

20. Soil Groups

21. Curriculum Alignment: Unit 4 – Site Planning Lesson 4.5 – Site Grading Act. 5.1 – Soil Testing

22. References: Dishongh, B.E. (2001). Essential Structural Technology for Construction and Architecture, Upper Saddle River, NJ: Prentice Hall Guthrie, P. (2003). Architects Portable Handbook: First Step Rules of Thumb for Building Design, New York, NY: McGraw-Hill Lindeburg, M.R. (1994). Civil Engineering Reference Manual, 9th ed. Belmont, CA: Professional Publications Inc

23. References: Sowers, G.F. (1979). Introductory Soil Mechanics and Foundations: Geotechnical Engineering, New York, NY: McMillian Publishing Unified Soil Classifications; http://www.hydro.unr.edu/homepages/bens on/classes/hydro/uscs.html.August 2004 US Army Unified Soil Classification System. http://www.adtdl.army.mil/cgibin/atdl.dll/fm/5 -472/apb.pdf.August 5, 2004

24. References: US Army Corps of Engineers. (1953). The Unified Soil Classification System, U.S. Army Technical Memorandum, No. 3-357.

25. Credits: Writer: Constance Bertucci Content Editor: Donna E. Scribner Narration: Donna E. Scribner PLTW Editor: Ed Hughes Production: CJ Amarosa Video Production: CJ Amarosa Audio: CJ Amarosa Project Manager: Donna E. Scribner